Process of making tubular bodies.



I VP. A. E. ARMSTRONG;

Patented Nov. 11, 1919.

PERCY A. E. ARMSTRONG, OF LOUIJONVILLE, NEW YORK.

PROCESS MAKING TUBULAR BODIES.

Specification of Letters Patent.

Patented Nov. 11, 1919.

Application filed January 17, 1919. Serial No. 271,610.

To all whom it may concern Be it known that I, PERCY A. E. ARM- STRONG, a subject of the King of Great Britain, and a resident of Loudonville, county of Albany, and State of New York, have invented certain new and useful Improve ments in Processes of Making Tubular Bodies, of which the following is a specification.

The present invention relates to a process for making tubular bodies, such as drill rod and the like. This invention is of that class in which tubular bodies are formed by first making a longitudinal aperture in a billet and placing a core therein, which core is reduced in cross section and elongated as the billet is rolled or otherwise elongated and reduced in cross section, and the core finally withdrawn, leaving atubular body.

The present invention is directed more particularly toward the prevention of welding from taking place between the material of the billet and core and facilitating the withdrawal of the core after the tubular body has been formed. This result is ob tained by providing between the billet and core a layer or layers of material which is infusible at the working temperatures used.

One mode of carrying out the present invention is by applying to the core (or to the interior walls of the billet bore, or both) a layer of metal which is adapted to be readily oxidized and furnishes an oxid layer which is not reduced upon coming into contact with heated steel. core may be plated with aluminum, or aluminum may be applied thereon as by paint-- ing with bronze, lacquer or the like, or in other ways, and after such layer has been oxidized, which may be readily done, for example, by subjection to fairly high heat in the presence of oxygen, a layer of oxid, as aluminum oxid, is obtained on the core, and with a core so treated welding is prevented from taking place during the rolling or other Working, and the withdrawal of the core from the completed tubular article may be readily carried out.

If desired, the core may be first given a coating, as by plating, of a metal which is not readily oxidized but remains in metallic form and is not melted at rolling temperatures, as, for example, a coating of nickel may be plated or otherwise applied on the core and the oxid or the like layer may be For example, the.

applied thereon over such metallic coatin as by coating the oxid thereon or by plating aluminum thereon and subsequently oxidizing the aluminum, or in yet other ways. Where a layer of metal such as nickel is used, the outer coating may be of various materials as talc, non-reducing metallic oxids, etc.

In the accompanying drawing I have shown, in Figure 1, a longitudinal. section of a bored billet having a two-piece core extending therethrough. Fig. 2 is a similar cross sectional viewyon an enlarged scale, of the completed tubular body prior to withdrawing the core. Fig. 3 is a fragmentary sectional view of a core having an oxid layer over a metallic layer.

In the form shown the core is in two pieces, which can be withdrawn from each end after working to get reduced cross section, as by rolling or the like, but it is to be understood that, while preferably the core is formed in two parts, as shown, and the withdrawal is thereby greatly facilitated, the invention is not limited to the use of a two-part core, as, for example, the core may be in a single piece. Also the core need not extend beyond the ends of the billet, as shown, but may be flush with the ends thereof, if desired. In such case the ends of the tubular body produced are cut or broken off in known manner with the core protruding at one end for pulling. The core or core parts may be secured in place within the billet in any desired way prior to rolling, as by being welded in place therein or the like. Making the core in two parts and withdrawing same from opposite ends is not claimed herein, but is described and claimed in my copending application, Ser. No. 271,609, filed on even date herewith.

The billet is designated by reference numeral l0 and has a longitudinal bore 11 therein. The two core parts are designated at 12 and 13, and the weld-preventing material, as aluminum oxid, is represented at 14:. Fig. 3 shows a portion of a core having a layer 15 of metal such as nickel, which may be obtained as by plating, and the layer of material 14, such as aluminum oxid over the nickel layer.

While I have referred to the use of nickel to be applied directly to the core, it is to be understood that other metals which will not melt or Weld at the temperature for rolling steel or the like, which is preferably used,

may be employed, and that instead of using aluminum and reducing it to an OXlCl, the use of other oxidizable metals may be resorted to, so long as the oxid is not reduced upon contact with steel or other carbon con.- taining metal at rolling temperature, or the oXid layer may be painted on or otherwise applied. The presence of the metallic layer, as nickel, is of advantage in making assur ance against welding more certain. \Vhile a layer of aluminum oxid, for example, is quite strong and coherent, if such layer should be broken or abraded at any point, welding will still be prevented ly the presence of the non-welding metallic layer un derneath.

It is to be understood that while, for simplicity of expression, my claims refer to the provision of the core with protective coat ings or layers, the invention also includes application thereof to the walls of the billet bore, if desired. lVhile the invention. has been described with reference to making steel drill rod, it is to be understood that it is applicable in making tubular bodies of various kinds and from various materials.

I claim:

1. The process of making tubular bodies such as drill rod and the like which consists in applying a coating of oxidizable metal to a core, oxidizing at least a portion of said metallic coating, inserting same in a longitudinally apertured billet, elongating and reducing the cross section of the billet and core and withdrawing the core, whereby a tubular body is produced.

2. The process of producing tubular bodies such as drill rod and the like which comprises introducing into a longitudinally apertured billet a. metallic core having a coating of aluminum oxid, reducing the billet and core in cross section and elongating same, and withdrawing the core from the tubular body formed.

3. The process of producing tubular bodies such as drill rod and the like which comprises introducing into a longitudinally apertured steel billet a metallic core having a coating of oXid which is not reduced upon contact with steel at rolling temperatures,

longatinp' and reducing the cross section of said billet and core, and withdrawing the core from the tubular body produced.

4. The process of making tubular bodies such as drill rod and the like which comprises plating a steel core with ya metal such as nickel which is'infusible at temperatures for rolling steel, plating the same with a plating of aluminum over the nickel, oxidizing the aluminum, inserting the core so prepared in a longitudinally apertured steel billet, elongating and reducing the cross sec tion of said billet and core, and withdrawing the core, whereby a tubular body is produced.

5. The process of making tubular bodies such as drill rod and the like which comprises coating a core with a non-welding metallic layer and with a layer of aluminum oxid over the metallic l: yer, introducing same into a longitudinally bored billet, elongating and reducing the cross section of the billet and core, and withdrawing the core from the tubular body formed.

6. The process of making tubular bodies such as drill rod and the like which comprises plating a steel core with a metal such as nickel which is not melted at temperatures for rolling steel, applying a further coating of weld-preventing material thereover, inserting the core so prepared in a longitudinally apertured steel billet, elongating and reducing the cross section of said billet and core, and withdrawing the core, whereby a tubular body is produced.

In testimony that I claim the foregoing, I have hereto set my hand, this 14th day of January, 1919.

PERCY A. E. ARMSTRONG.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

